The present invention relates to a milking apparatus for drawing a mother's milk into a container or bottle. More specifically, the present invention relates to a pressure adjusting mechanism for adjusting a suction created in the container used for storing the mother's milk. Also, the present invention specifically relates to a milking apparatus which prevents the counter flow of milk from the container when tipped or turned over, and also prevents clogging of the device with milk.
Milking apparatuses having an electrically powered suction device for drawing mother's milk are becoming increasingly popular to use. However, such milking apparatuses do not have improved suction action and thus tend to draw the mother's milk one-sidedly, overloading the breast, thus having a drawback of causing discomfort for the mother.
The applicant has already proposed, in Japanese Utility Model Application No. 141247/1984 (Japanese Utility Model Application Laid-Open Specification No. 54844/1986), a milker designed so that its suction pressure can be finely adjusted. This milker will now be described with reference to FIGS. 14 through 22. FIG. 14 is a complete perspective view of a milker and FIG. 15 is a fragmentary, enlarged vertical sectional view.
The milker comprises a bottle A for storing drawn mother's milk, a milking section B to be pressed against the mother's breast, and an electrically powered suction portion C for creating a suction or negative pressure in bottle these components being vertically connected together, so that the milking section B is interposed between the bottle A and the suction portion C in a linear fashion.
The milking section comprises a substantially cylindrical base portion 1, a barrel portion 2 extending generally horizontally from and integral with the upper portion of base portion 1. A funnel-shaped cup portion 3 spreads from the front end of barrel 2. The lower portion of the base portion 1 of milking section B terminates in a lower connecting portion 1a adapted to be threadedly engaged with the upper portion of bottle A. Further, the upper portion of base portion 1 terminates in an upper connecting portion 1b adapted to receive the lower portion of electrically powered suction portion C. Further, the junction between the barrel portion 2 of the milking section B and the cup portion 3 has a removable adapter 4 for reducing the diameter of the barrel portion 2. The adapter 4 is designed to closely contact the areola mammae of the mother's breast to increase the suction force or to compensate for small nipples, nipple depression or flat nipples.
The electrically powered suction portion C comprises a main body 5 fitted in the upper connecting portion 1b, an upper lid 6 fitted on the upper portion of main body 5, and an attaching body 7 disposed in the main body 5. Motor 8 and battery 9 which are electrically connected together by a wire (not shown) and are positioned on attaching body 7. The motor 8 has a crank pin 8a mounted thereon and the battery 9 can be replaced by removing the upper lid 9 from the main body 5. The main body 5 is in the form of two cases 5a and 5b which are vertically split. In FIG. 15, the left-hand case 5a is centrally formed with a vertical hole which holds a slidable switch 10 fixed in position by a screw 10a from the inside. A portion of the main body 5 is located below the switch 10 and adjacent the upper connecting portion 1b of the milking section B is formed with a horizontal hole 5c in which the pressure adjusting mechanism D is installed.
An exploded vertical sectional front view of the pressure adjusting mechanism D is shown in FIG. 16 and the same will now be described. In this figure, the left-hand side will be referred to as the outer side and the right-hand side as the inner side. The pressure adjusting mechanism D is formed with an open-air introducing hole 7a below the attaching body 7 and coaxial with horizontal hole 5c. Eight parts are fitted in said open-air introducing hole 7a: a compression coil spring a valve rod 12, packing 13, a valve seat 14, a pressure releasing button shaft portion 15, a pressure adjusting screw 16, a pressure adjusting knob 17 and a pressure releasing push button 18, in order from the inner side. The open-air introducing hole 7a is internally threaded at 7b. The valve seat 14 and the outer periphery of the inner side of the pressure adjusting screw 16 are externally threaded at 14a and 16a, respectively. The external threads 14a and 16a of valve seat 14 and pressure adjusting screw 16 are fitted to the internal thread 7b of the open-air introducing hole 7a. The valve rod 12 and packing 13 are fitted together and positioned in the open-air introducing hole 7a. Thereupon, the compression coil spring 11 urges the valve rod 12 outward to cause packing 13 to closely contact valve seat 14.
A sectional view of the pressure adjusting screw 16 taken along the line X--X is shown in FIG. 17, and a sectional view of the pressure adjusting knob 17 taken along the line Y--Y is shown in FIG. 18. As shown in the two figures, the pressure adjusting screw 16 and pressure adjusting knob 17 are formed with splines 16b and 17a (which are referred to as knurling in Japanese Utility Model Application Laid-Open Specification No. 54844/1986) and are thereby fitted and joined together. FIG. 19 is a sectional view showing them in this fitted and joined state and also showing the pressure releasing button shaft portion 15. In this figure, the reference numeral 5d denotes a stopper projecting from the case 5a at the upper edge of the horizontal hole 5c. The pressure adjusting knob 17 is internally formed with a locking piece 17b adapted to be arrested by the stopper 5d, whereby the angle of rotation of the pressure adjusting knob 17 is controlled so that it is within approximately 360 degrees.
The attaching body 7 of the pressure adjusting mechanism D has a suction or negative pressure generating section attached thereto, and an exploded sectional view of it is shown in FIG. 16. The suction or negative pressure generating section E comprises the attaching body 7, diaphragm 19 and cap 20. A right-hand side view of the attaching body 7 is shown in FIG. 20, a left-hand side view of the diaphragm 19 is shown in FIG. 21 and a left-hand side view of the cap 20 is shown in FIG. 22. The diaphragm 19 comprises a vibrating portion 19b outwardly projecting to form a suction chamber 19a, a suction valve 19c and an exhaust chamber 19d which are 90 degrees apart from each other. As bushing portion 19a extends outward from the vibrating portion 19b to fit on crank pin 8a. The suction valve 19c opens only inward, while the exhaust valve 19d opens only outward. The attaching body 7 is formed with a fitting hole 7c corresponding to the vibrating portion 19b, and a suction hole 7d and an exhaust hole 7e are formed at positions corresponding with the suction and exhaust valves 19c and 19d. Cap 20 is formed with a projection 20a corresponding to the recess 19a of the diaphragm and has a diameter smaller than the inner diameter of recess 19a. Cap 20 has first and second 10 narrow grooves 20b and 20c corresponding to the suction and exhaust valves 7d and 7e.
The open-air introducing hole 7a and suction hole 7d of the attaching body 7 communicate with the lower end of suction portion C through the air suction hole 7f. However, air suction hole 7f has a filter 21 fitted therein to prevent the milk from flowing back into suction portion C.
In FIG. 15, the lower end 5e of the main body 5 of suction portion C has a fitting ring 22 fitted thereon to elastically press the upper connecting portion 1b of the milking section B for a removable connection. Further, the lower side of the upper connecting portion 1b of milking section B is formed with a small hole 1c for and a guide ring 1d surrounds small hole 1c. The guide ring 1d prevents the milk from being drawn directly into small hole 1c . An annular packing 23 is installed between the lower connecting portion 1a of the milking section B and the bottle A to ensure close contact between the two parts A and B.
The operation of the above-described milker having fine adjustment of the suction pressure will now be set forth.
First, the cup portion 3 of the sucking section B is applied closely to the mother's breast and switch 10 is activated to turn the power on. Then, the crank pin 8a mounted on the motor 8 is eccentrically rotated, and diaphragm 19 engaged with the crank pin 8a is vibrated so that the air in the bottle A is drawn from the small hole 1c of the milking section through filter 21 to the air suction hole 7f of the sucking section C. Thus, a negative pressure is created in bottle A. Therefore, the mother's milk is drawn by the milking section B to flow along the barrel portion 2 of the milking section B and along the guide ring 22 into bottle A where it is collected.
In this case, if the pressure adjusting knob 17, engaged with the pressure adjusting screw 16, is turned counterclockwise, packing 13 engaged with valve rod 12 is moved away from the valve seat 14, allowing open air to flow from the horizontal hole 5c into the air suction hole 7f. Therefore, the suction pressure in bottle A decreases and accordingly so does the milking force or suction force, thus, resulting in gentle milking. Conversely, if the pressure adjusting knob 17 engaged with the pressure adjusting screw 16 is turned clockwise, the packing 13 engaged with the pressure adjusting screw 16 is pressed against the valve seat 14 so that open air will not flow into the air suction hole 7f. Therefore, the greatest negative pressure is created in bottle A so that the milk is strongly drawn by the milking section B. In this manner, by adjusting the degree to which the pressure adjusting knob 17 is turned, the suction force can be accurately varied.
Further, even if the packing 13, engaged with the valve rod 12, is pressed against the valve seat 14, the packing 13 engaged with the valve rod 12 and the valve seat 14 can be instantaneously separated from each other by simply pushing the pressure release push button 18. By pressing the pressure release push button 18, the open air is admitted into the air suction hole 7f through the horizontal hole 5c to reduce the suction pressure. Therefore, by intermittently pressing the pressure release push button 18, the mother's nipple can receive a suitable stimulus, similar to the suckling action of a baby, in order to enable an effective milking procedure.
Moreover, since the pressure adjusting knob 17 and the pressure release button push button 18 are installed on the lower lateral surface of the suction portion C, adjustment of the suction pressure can be made by one hand, while the mother's other hand may be free to be used to massage the periphery of her breast or to help in milking.
The pressure adjusting mechanism D, described above, is composed of a total of 11 parts, including the attaching body 7 and the negative pressure creating section E in order to make it possible to provide for accurately adjustable suction pressure. The manufacture and assembly of such a large number of parts is time consuming and expensive. Thus, a disadvantage of the above-described milker is that it is expensive and time consuming to produce.
Another disadvantage of the above-described milker is that the small hole 1c can often become clogged up. Specifically, if the suction force of the milker is too strong, the mother's milk becomes atomized as it is drawn out, and travels around guide ring 1d and coagulates at small hole 1c in the milking portion B. thus, when the small hole 1c is clogged up, even when the suction portion remains on, the milking process will deteriorate and stop.
A further disadvantage of the above described milker is that when the bottle A is turned sideways, or is tipped over, the mother's milk collected in the bottle will flow into air suction hole 7f from small hole 1c by way of filter 21. Then, the milk flows into the motor mechanism and causes faults in the operation of the motor. This disadvantage occurs often, because milking is often performed in the bedroom, and the milking apparatus is likely to be placed on an unstable surface such as a mattress. Such an unstable surface often results in the milking apparatus being tipped over, causing the milk to contaminate the motor mechanism.